Diodes Incorporated MMBZ5227BW-7

Overview

MMBZ5227BW-7 from Diodes Incorporated is a 3.6 V, 200 mW surface-mount Zener diode in SOT323 package, rated for ±5% zener voltage tolerance at 20 mA test current, with 24 Ω zener impedance and 15 μA reverse leakage at 1.0 V reverse bias. It serves as a precision voltage reference or overvoltage clamp in low-power analog signal conditioning circuits.

For engineers reviewing the MMBZ5227BW-7 datasheet, MMBZ5227BW-7 pinout, MMBZ5227BW-7 application, or MMBZ5227BW-7 equivalent, key selection criteria include nominal zener voltage (3.6 V), power rating (200 mW), zener impedance (24 Ω @ 20 mA), reverse leakage (15 μA @ 1.0 V), and AEC-Q101 qualification for automotive-grade reliability.

Technical Context

This Zener diode operates in reverse breakdown mode to maintain stable voltage regulation across varying load currents. Its 3.6 V nominal zener voltage is specified at 20 mA test current, with tight 3.42–3.78 V min/max range and 24 Ω dynamic impedance measured at 1 kHz, ensuring predictable clamping behavior in feedback or protection paths.

Designed for surface-mount assembly on FR4 PCBs with recommended pad layout (AP02001), it features matte tin-plated Alloy 42 leads, moisture sensitivity level 1, and UL 94V-0 molded plastic case - enabling compatibility with automated reflow processes and high-reliability industrial and automotive applications.

Key Specifications

Pinout & Package

Package: SOT323 - 3-terminal surface-mount plastic package with 0.65 mm pitch, 2.10 mm × 1.30 mm footprint, and 0.30 mm profile; compatible with JEDEC-standard reflow profiles and automated pick-and-place.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Zener diode voltage reference applications.

Compared with BZX384-B3V6,115 and MM3Z3V6T1G, MMBZ5227BW-7 offers lower zener impedance (24 Ω) and AEC-Q101 qualification - making it preferred for automotive and high-stability analog references where voltage regulation precision and reliability are critical.

Availability

MMBZ5227BW-7 is available at Aetrix Electronics and suitable for automotive cabin sensors, industrial temperature transmitters, and medical wearable battery monitors requiring stable component supply and long-lifecycle support.

Supply support for MMBZ5227BW-7 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design and manufacturing operations across Asia and the Americas.

The MMBZ52xxBW series belongs to Diodes' precision Zener diode product line, engineered specifically for voltage regulation and reference applications in space-constrained, high-reliability environments including automotive, industrial, and medical electronics.

FAQ

What is the maximum reverse voltage that can be continuously applied to MMBZ5227BW-7 without breakdown?

The device is designed to operate in reverse breakdown at its nominal 3.6 V zener voltage. Continuous reverse voltage below 1.0 V results in only 15 μA leakage; applying >3.78 V (max zener voltage) risks exceeding power limits. For safe non-breakdown operation, keep reverse bias ≤1.0 V unless intentional regulation is intended.

Does MMBZ5227BW-7 require a series current-limiting resistor in all applications?

Yes - a series resistor is mandatory to limit zener current to ≤20 mA under worst-case supply conditions. Without it, excessive power dissipation (>200 mW) will cause thermal runaway. Typical values range from 1 kΩ (for 5 V supplies) to 10 kΩ (for 3.3 V supplies with light loading), calculated using (V_SUPPLY − 3.6 V)/I_Z.

How does the SOT323 package affect thermal performance compared to larger packages like DO-35?

SOT323 has higher thermal resistance (625 °C/W) than DO-35 (~300 °C/W), limiting usable power to 200 mW at +25°C ambient. At +85°C ambient, derated power drops to ~120 mW. This makes it unsuitable for high-current regulation but ideal for low-power reference and protection roles where size and automation compatibility outweigh thermal headroom.

Is MMBZ5227BW-7 suitable for use in 12 V automotive load-dump protection circuits?

No - its 3.6 V zener voltage and 200 mW rating make it inappropriate for clamping 12 V transients, which require higher voltage ratings (e.g., 13–15 V) and surge power capability (≥1 W). It is instead suited for low-voltage internal rail clamping (e.g., 3.3 V or 5 V domains) or precision reference generation upstream of protection stages.